During closing arguments, federal prosecutor Robert Heberle told jurors that Lundergan was involved in a "concerted scheme" to subvert federal election rules to benefit the campaign of Alison Lundergan Grimes, who is Kentucky's secretary of state.

"These were secret payments because the defendants knew what they were doing was wrong," Heberle said at the start of a full day of closing statements.

Lundergan and another defendant — veteran Democratic consultant Dale Emmons — are accused of taking part in a conspiracy to direct illegal contributions to Grimes' high-profile Senate campaign at a time when she was seen as a rising Democratic star.

If convicted, both men could face lengthy prison sentences. Their attorneys called just two witnesses before wrapping up their defense earlier this week. Alison Lundergan Grimes was in the courtroom Wednesday. She had been a potential witness but was not called to testify.

Jerry Lundergan's attorney, J. Guthrie True, said prosecutors failed to show any evidence of criminal intent while trying to establish ties between the campaign and Lundergan's company.

"This was not an investigation of a crime, but an investigation of something to call criminal," True said during his closing arguments.

The defense attorney acknowledged that mistakes were made but added: "You don't convict people for mistakes."

Emmons' attorney, Brandon Wayne Marshall, stressed in his closing arguments that his client didn't understand the intricacies of federal campaign-finance law and also argued that "mistakes are not crimes."

The case is expected to go to the jury Thursday.

Prosecutors allege that Lundergan funneled more than $200,000 in illegal contributions to Grimes' campaign, either by paying for campaign services directly and not seeking reimbursement or by paying costs through Emmons.

Heberle displayed a series of emails and campaign invoices Wednesday to back up his allegations that Jerry Lundergan and Emmons conspired to conceal the corporate contributions from Grimes campaign compliance officials.

True countered that Jerry Lundergan had no reason to resort to corporate contributions since his daughter's campaign received massive amounts of donations. The campaign raised enough in four days to pay for all the services prosecutors claim were covered with corporate help, he said.

True also noted that the government's case focused on Grimes campaign expenses in 2013 — a year before the election.

"If a man had the intent to use his corporate resources to help his daughter's campaign, wouldn't you think he'd do it when it really mattered?" True said.

True told jurors that "everything was done in the light of day," adding: "The government has treated Jerry like a heel in this case for trying to help his daughter's campaign."

The defendants are longtime friends and well-known political figures in Kentucky. Jerry Lundergan, a Lexington businessman, is an ex-state lawmaker and former state Democratic Party chairman. Emmons has worked on campaigns for offices from courthouses to Congress.

Grimes, one of the state's most prominent Democrats, is finishing her second term as Kentucky's secretary of state and cannot seek reelection this year because of term limits. She considered running for governor this year but decided against it.